Flexible tube pump



Jan. 13, 1970 w. GEMEINHARDT FLEXIBLE TUBE PUMP Filed May 8. 1968 3Sheets-Sheet l F/Gll/ Jan- 13 1970 w. GEMEINHARDT 3,489,097

FLEXIBLE TUBE PUMP ATTORNEYJc Jan. 13, 1970 w. GEMEINHARDT 3,489,097

FLEXIBLE TUBE PUMP Filed May e. 196e 3 Sheets-Sheet 3 INVENTOR W/l A4/VGENE//V/M United States Patent O 3,489,097 FLEXIBLE TUBE PUMP WilliamGemeinhardt, 143-45 Ash Ave., laughing, N Y. 1135s Filed May s, 196s,ser. No. 727,517 Int. Cl. F04b 43/08 U.S. Cl. 103-148 13 Claims ABSTRACTOF THE DISCLOSURE A pump having a llexible, tubular chamber and valveportions and a device for selectively compressing the chamber and valveportions including two valve actuating members mounted to a single,oscillatable rocker plate actuated by an eccentric which also actuatesthe plunger acting to compress the pump chamber, the synchronization ofthe valve actuating members and plunger being such as to provide a ilowof fluid through the flexible, tubular member.

BACKGROUND OF THE INVENTION Flexible tube pumps, that is, thoseemploying some type of flexible member for both the chamber and valvesof the pump, where various mechanisms act on the flexible member toprovide the pumping action, are known to the art. Many of these areextremely complex in sructure employing standard cams or cranks andlevers for movement of all operating parts of the device. They arerelatively expensive, or are relatively limited as to the ability tovary the operation of the mechanism to provide dierent eiects.Additionally, these devices generally require extensive lubrication andmaintenance and are difficult to protect from dirt and corrosion.Further,

with many of the prior art pumps there are problems with both creepingof the tubular member and with backliow of the fluid, during pumping.With respect to this creeping problem, it has often been solved byforming only the portion of the tube actually acted upon by themechanism, of a llexible material and joining the flexible material, atits extreme ends, to a relatively solid pipe material. In thissituation, much of the advantage of the flexible tube pump is lost.

In accordance with the present invention, a device has been developedwhich can easily be attached to a straight line liexible member, toconvert a portion of that member into a pump, without cutting or bendingof the flexible, tubular member. This device can be used to dispense orextract measured quantities of liquids or gases, including thedispensing or extracting of very small quantities, such as a fraction ofa drop.

Further, the art has required, and according to the present invention,there is provided a liexible tube pump wherein the pressure and thecapacity can be easily changed during operation. Still further,according to the present invention a flexible tube pump can be providedwhere, without cutting or mounting of the flexible tube on tube holders,there is little or no tendency for the tube to creep and tube life issignificantly enhanced due to the particular construction. In addition,backflow within the pump is significantly minimized, or eliminated. Thisflexible tube pump requires a minimum of maintenance as it employs aminimum number of parts and those parts subjected to sliding frictioncan be made selflubricating.

SUMMARY OF THE INVENTION In accordance with the present invention, adevice has been developed which can be placed at any point along astraight run of iiexible, tubular material to cause that portion of theflexible, tubular material to act as a pump.

3,489,097 Patented Jan. 13, 1970 ICC The device is extremely simple inoperation and has a minimum of moving parts.

As with the prior art devices for similar purposes, it comprises onemember to act upon the flexible, tubular member in the manner of aninlet valve, a second member to act upon the flexible, tubular member asan outlet valve, and a plunger to provide the pumping action within theflexible, tubular member. However, in the device of the presentinvention, both valve actuating members are attached to a single rockerplate. Only a single spring is provided for this rocker plate andadjustment of that spring is effective to vary the pressure of the pump.

One of the valve actuating members is always so positioned as to closethe corresponding valve portion. When either valve actuating memberrises to open the corresponding valve so as to permit a flow of fluid,the open ing is limited, by the device, to about 20% of the diameter ofthe tube.

The rocker plate is oscillatable about an attached pin which is slidablein an elongate slot. The rocker plate is moved by an eccentric whichacts upon an upper surface of the rocker plate to provide theoscillating action and the combination of the resilience of theilexible, tubular member and the spring acting on the rocker plate, actto cause the pin to which the plate is attached to move within theelongate slot. This combination also acts as a safety valve to preventoverpressuring of the flexible, tubular member. A device can also beformed, wherein two upper surfaces are formed on the rocker plate,diametrically opposed with respect to the eccentric, so that thiseccentric acts to move the rocker plate in each oscillation direction.

Also in operative relation with the eccentric is a rod, joined to theplunger actuating the pump portion of the flexible, tubular member, Thisrod is also spring loaded so as to return it to its uppermost position,and cause it to move with the eccentric. In other embodiments, this rodcan be broken away and a portion replaced by a high compression spring.Thus, if the plunger comes in contact with solid material within thetubular member, the high compression spring will compress to prevent theplunger from attempting to close, through completely solid connections,on the solid material. Such a solid closure could damage or destroy theplunger, the tubular member, and the base plate upon which the tubularmember rests.

When pumping at faster rates or when it is desired to deliver shorterspurts of the liquid, the eccentric can be directly coupled to astandard cam so formed as to depress the plunger more quickly and allowit to open more quickly. This allows the pumping portion of theflexible, tubular member to remain open longer for filling during eachcycle.

The angle at which the eccentric contacts the upper surface of therocker plate can also be varied to obtain certain advantages. Thus, therocker plate can be inclined to keep the inlet valve of the device in amore open position.

This, too, is more advantageous when the pump is ernployed for viscousmaterials or for slurries. Further, other adjustments of this sameadjusting member can change the phase relationships of the inlet andoutlet valves and the plunger. As is understood in the art, the normalrelationship causes the inlet valve to open while the plunger is movingupwardly, the inlet valve to then close while the plunger is in anupright position, the outlet valve to open, and the plunger tothendepress in order to pump the lluid through the llexible, tubular member.Thereupon, the outlet valve again closes and the inlet valve opens tostart a new cycle.

Below the two valve actuating members and the plunger a solidly mountedbase plate is located. The ends of this base plate are cut out to a sizeto match the diameter of the exible, tubular member and are indented toa degree that the innermost portion of the slot is in vertical alignmentwith the respective valve actuating member. Thus, in operation, theilexible, tubular member is depressed, to a degree, below the horizontallevel of the base plate. This positioning aids in preventing theiiexible, tubular member from creeping perpendicular to its axis duringoperation of the device. As a further aid in preventing creeping of theflexible, tubular member along its axis, the elongate slot in which therocker plate pin slides can be angled toward the inlet of the pump.Thus, any tendency of the tubular member to move toward the outletdirection is counteracted by the motion of the rocker plate, and thusthe valve actuating members, in the direction of the inlet.

The volume pumped through the iiexible, tubular member employing thedevice of the present invention can be easily varied, during operation,by a single adjustment affecting the amplitude of the plunger motion.Thus, maximum volume is delivered by allowing the plunger to movethrough its full amplitude. By a simple adjustment, the plunger can beprevented from moving to its full upward position, thus cutting down theamplitude and, effectively, diminishing the volume of the chamberportion of the exible, tubular member. By this simple adjustment,accurate control can be maintained over the volume which the pumpdelivers, including accurate measurement to as small a volume as drops,or fractions of drops, per pumping cycle.

Thus, it is an object of the present invention to provide aninexpensive, compact pumping device, employing a exible, tubular member,which is simple in construction rand operation, and needs littlemaintenance, but is capable of dependable performance and easy variationof operation.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. 1 is an elevational view of one embodiment of the presentinvention;

FIG. 2 is a view, along the line 2 2 of FIG. l;

FIG. 3 is a sectional View along the line 3 3 of FIG. 1 showing theconstruction of one embodiment of the plunger rod ofthe device;

FIG. 4 is a sectional view along the line y4 4 of FIG. 1 showing theconstruction of the pressure regulating portion of the device;

FIG. 5 is a view along the line 5 5 showing the elongate slot in whichthe rocker plate pin is slidable;

FIG. 6 is an elevational partial sectional view of the device, along theline 6 6 of FIG. 3 showing the rocker plate and plunger in lillposition;

FIG. 7 is a view of the base plate of the device, showing thepositioning of the flexible, tubular member, taken along the line 7 7 ofFIG. 1;

FIG. 8 is an elevational view of a second embodiment of the deviceshowing a modified rocker plate and eccentric assembly with an addedcam;

FIG. 9 is a View taken along the line 9 9v of FIG. 8;

FIG. 10 is a sectional view along the line 10-10 of FIG. 8 showing theconstruction of the eccentric with the added cam and of a secondembodiment of the plunger rod; and

FIG. l1 is a fragmentary view of a modified rocker plate and bearingring showing a means for adjusting the relationship between these parts.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, FIG.l shows a plan view of the overall device 1 having a rocker plate 2 withattached valve actuating members 3 and 4 which act on flexible, tubularmember 5. To this rocker plate is attached pin 6 which is slidable inelongate slot 7. This elongate slot is formed in a plate 8 held by tabs9 and 10 to the support bracket 11 of the structure. Tabs 9 and 10 areheld against the support plate 11 by threaded members 12 and 13. Theplate 8 is movable as shown in phantom 8 in order to vary the angle ofthe elongate slot 7 which is normally in a generally vertical position.This, as previously described, is an aid in preventing creeping of theflexible, tubular member 5. The elongate slot 7 and plate 8 are soformed that the elongate slot is always in juxtaposition with theopening 14, shown in hidden lines, in the support member 11.

Stud 15 is slidable in opening 65 formed in support member 47. As shownin FIG. 4, this stud 15 bears against Valve actuating member 4 totransmit the pressure of spring 16 to rocker plate 2. It should beunderstood that this is -merely one convenient method of applying springpressure to rocker plate 2 and that, for example, a bearing member couldbe attached to the rocker plate solely for receiving this springpressure, and thus transmitting the pressure to both valve actuatingmembers.

The support member 47 can be formed of a self-lubricating material toprovide for easier movement of parts, such as stud 15, and to avoid thenecessity of providing constant lubrication. For example, it can beformed of carbon-graphite, nylon, graphite filled synthetic resins, etc.

Adjustable member 17 bears against spring 16 to control the pressuretransmitted by the spring. The adjustable member comprises a threadedportion 1S, threadably received in support member 47, and a rod member19 connected to adjusting knob 20. As this member 17 is moved downward,through action of the screw threaded portion, the pressure transmittedby spring 16 is increased and the pressure at the outlet of the pump iscorrespondingly increased.

Downward movement of the flexible, tubular member 5 is limited byplacement of base plate 30 which is mounted to support member 11 byscrew members 31 and 32, below the plane of the valve actuating members3 and 4. Adjustment of the height of this base plate is accomplished byadjusting members 33, 34, 35, and 36 which determine the height of thebase plate and its relative distance from the valve actuating members,and also control the inclination of the base plate.

Cutout portions 37 and 38 are formed at the ends of the base plate 30.The width of each cutout portion 37 and 38 is the same as the diameterof the largest flexible,-

tubular member 5 preferably accommodated by the device. The length ofthe cutout portions is such as to place the ends of the cutout portions39, 39 in juxtaposition to the respective valve actuating members 3 and4. Thus, the flexible, tubular member, in its normal position, has aportion lying below the horizontal plane of the base plate. As the valveactuating members are lowered they compress the iexible, tubular memberagainst the surfaces 39, which aids in preventing creeping of theflexible, tubular member during operation of the device.

As the clearance between valve actuating members 3 and 4 and base plate30 is relatively smaller than the diameter of exible, tubular member 5,there is often some difliculty in inserting the iiexible, tubular memberinto its proper position. As an aid in inserting this member, a leverarrangement 70 is provided, as best seen in FIG. 5. The lever has ashorter end 71 against which pin 6 of rocker plate 2, in its lowermostposition, rests. The lever assembly is pivoted about pin 72 and isactuated by an elongate handle 73, shown broken away. Depression of theelongate handle 73 causes the shorter end 71 of the lever to cause pin 6to move upwardly in elongate slot 7. This causes rocker plate 2 to moveupward, away from the base plate, and thus moves valve actuating members3 and 4 away from the base plate, to allow for easier insertion offlexible, tubular member 5.

The actual pumping of fluid is accomplished through the action ofplunger 40, which lies generally in the plane of the valve actuatingmembers, on that portion of the tlexible, tubular member lying betweenthe valve actuators 3 and 4. Motion is transmitted to this plunger byrod 41 joined to plunger 40 by threaded member 42. This rod member 41,and thus the attached plunger 40, are maintained in a normally upperposition, through the action of spring member 43.

Upward movement of the plunger is limited by rod member 44 which isthreadedly adjustable by means of screw threaded portion 45, which actsin corresponding thread members formed in face plate 46. A portion ofthe rod `passes through an opening 48 in support member 47. This rodmember can be moved by an adjusting knob 49 mounted to the top of thescrew threaded portion 45. Adjustment of this rod member 44 with thecorresponding limitation in upward movement of the plunger 40 determinesthe volume of tiuid which enters the central chamber portion of theflexible, tubular member 5, and thus controls the capacity of the pump.Maximum capacity is attained when this rod member is in its uppermostposition, allowing for full travel of rod 41 and plunger 40. As theadjusting knob 49 is turned so as to move rod 44 downwardly, throughaction of the threaded portion 45, the upward movement of the plunger isrestricted, preventing it from allowing full expansion of the centralportion of flexible, tubular member 5, and thus restricting the quantityof fluid which can be taken into the chamber portion of the tubularmember. Further, with the limitation on upward motion, the downwardstroke of rod 41 is foreshortened, thus reducing the quantity of fluiddispensed on each stroke of the rod 41. Thus, by

restricting motion of the plunger rod 41 to the proper degree, extremelysmall, accurately measured quantities of fluid can be dispensed from thefiexible, tubular member, including quantities of drops, and fractionsof a drop, on each stroke.

Motion of both the valve actuating members 3 and 4 and plunger rod 41 iscaused by rotation of eccentric 50, through action of bearing ring 51 onsurface 52 of rocker plate 2 and on the top of plunger rod 41 whichactuates plunger 40. Eccentric 50 is journalled within the bearing ring51 through ball bearings 53, or other equivalent bear ing means. Thesebearing means are lubricated and sealed so as to preclude the access ofdirt and moisture and prevent the need for continuous lubrication.

As the eccentric rotates, in a clockwise direction as viewed in thedrawings, it first forces the rocker plate 2 to the left, as moreparticularly shown in FIG. 6. This allows inlet valve actuating member 4to rise up, while outlet valve actuating member 3 remains in itslowermost position to seal flexible, tubular member 5, also as moreparticularly shown in FIG. 6, and thus allows tiuid to enter theflexible, tubular member 5. As the rotation of eccentric 50 continues,the inlet valve actuating member 4 begin to descend, thus compressingthe tube in the vicinity of the inlet valve actuating member to closethat valve, and the outlet valve actuating member 3 then rises openingthe outlet valve about of the tube diameter. As the outlet valveactuating member 3 continues to rise due to continued motion ofeccentric 50, the spring action of the flexible, tubular member 5, andthe motion of pin 6 within elongate slot 7, the plunger 40 is depressedby the downward movement of plunger rod 41, carried out through actionof eccentric 50 through bearing ring 51. The purpose of the bearingsbetween eccentric 50 and bearing ring 51 is to allow for continued freemovement of the eccentric, notwithstanding any frictional binding of thebearing ring against either the top of plunger rod 41 or surface 52 ofrocker plate 2.

Face plate structural member 46, which is bent to form a face platecovering the operating components is bonded to structural member 47through screw member 60, which is also attached to the motor casing.

Modified forms of various components of the device are illustrated inFIGS. 8, 9, l0` and 11. In FIG. 8 there are shown, with the samestructure as in FIG. l, the structural member 11 and base plate 30mounted by screws 31 and 32, along with adjusting nuts 33, 34, 35, and36. Also, in the same form as in FIG. 1 are the structural member 47 andvalve actuator adjusting member 17 with screw threaded portion 18, rod19 and adjusting knob' 20. The rod member 44 for limiting the travel ofthe plunger including screw threaded portion 45 and adjusting knob 49are also as shown in the first embodiment.

The variation in FIGS. 8 through 11 involve, generally, rocker plate102, eccentric and cam assembly 149, plunger rod 141, and a means foradjusting the contact between a rocker plate 202 and bearing ring 51. j

Particularly when pumping especially viscous fluids, or slurries, agreat deal of work must be expended by the device in moving the fluidthrough the flexible, tubular member. Further, more pressure is requiredon the flexible, tubular member by the valve actuating member in orderto assure proper closure. Under these circumstances, complete reliancecannot always be placed upon the single surface of the rocker plate andthe spring acting on the rocker plate. However, more positive action canbe imparted to the rocker plate, and hence to the valve actuatingmembers, merely by a second leg as on the rocker plate 102, with thissecond leg in contact with the eccentric 150. This is illustrated inFIG. 8 where the rocker plate 102 has a first leg with a surface 152, asin the first embodiment, but additionally, has a second leg 154, shownin phantom, with a bearing surface 155. The construction of theeccentric journalled in the bearing ring 151 through a bearing surface,such as ball bearings 153, is essentially the same as shown in the firstembodiment. Here, however, the bearing ring acts first against surface152 to force the rocker plate toward the left, as with the firstembodiment, but then, in continuing its clockwise rotation, positivelyacts against surface 155 to force the rocker plate toward the right, asviewed in FIG. 8, and thus positively acts on the inlet Valve actuatingmember 104 to compress the tubular member and thus close the inletvalve. The construction of the inlet valve actuating member 104 andoutlet valve actuating member 103 are the same as in the firstembodiment. Similarly, the modified rocker plate 102 is mounted to pin106, which similarly rides in an elongate slot (not shown).

When the device operates at higher speeds, often the chamber portion ofthe flexible, tubular member 5 cannot be completely filled in the timeallotted by rotation of the eccentric within the bearing ring. This canbe provided for by maintaining plunger rod 141 in its upper positionduring a longer portion of the cycle. This is accomplished by rigidlyattaching to the face of the eccentric 150 a cam 156. This cam 156 actsdirectly on plunger rod 141, rather than the bearing ring 151 makingcontact with this plunger rod 141. The cam 156 has only one high spot157 which acts to depress the plunger rod 141. Thus, this single highspot 157 is the only portion of the cam surface which provides fordepression of the plunger 140 and plunger rod 141, so that a rapiddepression is achieved, rather than the relatively gradual depressionachieved were the surface of bearing ring 151 employed to depress theplunger 141. This type of configuration is also employed to produce amore pulsating fiow than obtained with the construction of the firstembodiment.

The modified plunger rod construction is more clearly shown in FIG. 10.Here, it can be seen that the modified plunger rod 141 is formed with anupper section 160, which is acted upon by the surface of the cam 156,or, in the first embodiment, by the surface of bearing ring 51. Thisupper portion 160 slides within opening 161 provided in structuralmember 47. Upper portion 160 is provided with shoulder 162 and opening161 is provided with shoulder 163 for support of spring member 164 whichis also within opening 161. This spring member 164 causes return ofplunger rod 141 and plunger 140 to their uppermost position as allowedby the positioning of bearing ring 51 or cam 156. Plunger 140 isattached to screw member 165 having head 166. This screw member lieswithin center opening 167 in upper portion 160. Downward motion of thescrew member 165 and plunger 140 is limited by shoulder 168 on upperportion 160 which retains screw head 166. Within opening 167, abovescrew head 166, is high compression spring member 169. This springmember 169 is retained in position by and the compression can beadjusted by screw threaded member 170. Member 171 is a lock nut toretain plunger 140 in its position on screw member 167.

This type of construction for the plunger rod 141 is particularlyadvantageous when the pump is employed for the pumping of slurries. Bydefinition, such slurries contain undissolved solid material. In somecases, the dimensions of these solid materials are substantial and,employing the plunger rod 41 of the first embodiment, there is danger ofdamaging one or more of the eccentrics 50, bearing ring 51, plunger rod41, plunger 40, base plate 30, or, particularly, the exib'le, tubularmember 5 when the plunger and plunger rod are depressed to pump fluidfrom the central, chamber portion of the flexible, tubular member. Onlya solid connection is possible and, if the dimensions of the solidparticles are greater than the clearance normally provided, then damagecan result. With the modified construction of plunger rod 141, thepossibility of such damage is ameliorated. The spring force of springmember 169 is sufiicient to normally provide an essentially solidconnection between the eccentric surface or cam surface and plunger 140.However, if a piece of solid material of relatively large dimensions iscontained within the central portion of iiexible, tubular member 5, thenthe spring 166 will compress and thus, effectively, shorten the strokeof plunger rod 141, thereby increasing the clearance between the plunger140 and the base plate 30. Similar problems are not presented by thevalve actuating members 103 and 14, due to the mounting of rocker plate2 or 102 on pin `6 or 106, moving in an elongate slot such as 7. Theextra dimension of the solid particle will merely cause the rocker plateto ride up, through action of the pin within the elongate slot.

To provide for accurate pumping of small quantities, such as drops orfractions of drops, backflow Within the flexible, tubular, member mustbe avoided. Backiiow is caused by opening of the outlet valve, beforethe start of pumping action by the plunger.

The cutouts provided in the base plate 30, the inner edges of which arein alignment with the valve actuating members, aid in minimizingbackflow within the pump. The avoiding of backflow is necessary toprovide for accurate pumping of minute quantities, such as drops orfractions of drops. With the cutout construction, the tube, aspreviously shown and described, falls partially through the cutouts.When the valve actuating member rises, the flexible, tubular member alsomoves up, to some degree, within this cutout and this avoids the suddenrelease of pressure common in most flexible tube pumps. However,backflow can be essentially eliminated by changing the phaserelationship bet-Ween the outlet valve actuating member and the plunger.This can be accomplished by means of the structure shown in FIG. 11.

A rotatable post 180, having threadably mounted therein screw member 181is provided on a modied rocker plate 202 to allow for changing of therelationship of rocker plate 202 with respect to bearing ring `51. Thescrew member is provided with lock nut 182. When the rotatable post isso located that screw member 181 is in a generally horizontal alignment,the screw member 181 can be advanced through the rotatable post 180 soas to displace surface 252 slightly from the surface of bearing ring 51.Thus, the actual contact between the rocker plate 202 and the bearingring 51 is through the end of screw member 181. By varying the angle ofrotatable post 180, and the advancement of screw member 181, the rockerplate 202 can be so angled that inlet valve actuating member 4 is raisedfurther from the base plate, while placing outlet valve member 3 closerto the base plate. This adjustment also allows for correction ofinaccuracies in the formation of rocker plate 202 or valve actuatingmembers 3 and 4. Further, inaccuracies in base plate 30 can also becorrected by this adjustment, though, of course, the base plate 30 canbe adjusted, itself, through screw members 31 and 32 and nuts 33, 34, 35and 36. Such an arrangement is also advantageous for the pumping ofviscous iiuids, Where a wider opening in the inlet valve is desirable toallow for filling of the central, chamber portion of flexible, tubularmember 5 during the pumping cycle.

Employing a device as previously described with a flexible rubber tubehaving an internal diameter of about one-half inch, the pump device candeliver about 230 cc.s per minute with a 1/250 horsepower motor, at 70revolutions per minute. Obviously, other tubing diameters, motors, andrevolution rates can be employed.

Because of the construction of the device of the present invention,including the mounting of the rocker plate pin in an elongate slot, theentire operating mechanism of the device which comes in contact with theflexible, tubular member will move up or down, in response to differingtube wall thicknesses. Thus, the device of the present invention is farmore adaptable than those of the prior art.

The portion of the flexible, tubular member lying beneath the valveactuating members are, in normal operation, never allowed to expand tomore than about 20% of their full diameter. Thus, there is significantlyless flexing of the tubular member employing the device of the presentinvention, which limits Wear on the tube.

In some applications, it may be desirable to allow for a controlledamount of creep of the flexible, tubular member. For example, thiscontrolled creep would aid in avoiding wear on the flexible, tubularmember, as the valve actuating members and plunger would strikedifferent portions of the flexible, tubular member. The ability to anglethe elongate slot in which the rocker plate pin rides provides thecapability of controlling this creep. Thus, if desired, this elongateslot can be angled in a forward direction about 15 which would providefor about one-quarter inch of creep for each hours operation of thepump.

Thus, an improved device for acting upon a flexible, tubular member toprovide a pumping action has been shown and described. These devices aresuperior to those of the prior art, both in operation and in ease andeconomy of construction.

What is claimed is:

1. A pump having for the chamber and valve members a flexible, tubularmember, said member acted upon by a device comprising:

(a) a rocker plate having mounted thereon an inlet valve actuatingmember and an outlet valve actuating member;

(l) said rocker plate mounted on a pin slidable in a generallyvertically disposed elongate slot,

(b) a plunger, disposed above the central portion of the flexible,tubular member which acts as the pump chamber,

(l) a rod for actuating said plunger;

(c) an eccentric acting upon said rocker plate for movement of the inletvalve actuating member and outlet valve actuating member, and on theplunger rod for actuation of the plunger;

(d) a base plate mounted below the plane of the inlet valve actuatingmember, outlet valve actuating member, and plunger, for supporting theflexible, tubular member.

2. The device of claim 1 wherein the eccentric is iournalled, through abearing surface, into a bearing ring which makes contact with an uppersurface of the rocker plate and with the plunger rod.

3. The device of claim 2 wherein the rocker plate is provided with twosurfaces for direct contact with the bearing ring.

4. The device of claim 2 wherein adjustable means are provided, adjacentthe contact surface of the rocker plate, to vary the relationshipbetween the valve actuating member and the plunger.

5. The device of claim 2 wherein said plunger rod is formed in twosections, a lirst section contacted by said bearing ring and a secondsection connected to the plunger, the two sections being joined by aspring member.

`6. The device of claim 1 wherein said elongate slot is rotatable tovary the motion of the rocker plate.

7. The device of claim 1 wherein the base plate is provided With cutoutportions to allow for depression of a portion of the exible, tubularmember into a plane beneath that of the vbase plate, the edges of saidcutout portions lying below the respective inlet valve actuating memberand outlet valve actuating member.

8. The device of claim 1 wherein said eccentric is journalled within albearing ring and a cam member is attached to the face of saideccentric, the bearing ring acting upon an upper surface of the rockerplate and the cam acting upon the plunger rod.

9. The device of claim 1 wherein the rocker plate can be moved manuallyupward through motion of the pin within the elongate slot, throughaction of a lever, to allow for easier insertion of the flexible,tubular member.

10. The device of claim 1 wherein adjustable means are provided to varythe capacity of the pump, said means being adjustable during operationof the device to limit upward motion of the plunger.

11. The device of claim 1 wherein adjustable means are provided to varythe pressure of the pump output, said means comprising a spring member,the compression of which is adjustable during operation of the device,acting against the rocker plate.

12. A pump employing, as the chamber and valve members, a flexible,tubular member, and a device for acting upon said flexible, tubularmember comprising:

(a) a rocker plate having mounted thereon an inlet valve actuatingmember and an outlet valve actuating member,

(1) said rocker plate mounted upon a pin located in an elongate slot,

(2) said elongate slot being rotatable;

(b) a plunger for contact with the chamber portion of said flexible,tubular member,

(1) a rod attached to said plunger for actuating said plunger,

(2) said rod being formed in two sections, a first upper section, and asecond lower section attached to said plunger, said sections `beingjoined by a spring member;

(c) an eccentric journalled within a bearing ring,

(1) the surface of said bearing ring contacting an upper surface of saidrocker plate and the upper section of said plunger rod;

(d) a base plate mounted below the plane of the inlet valve actuatingmember, outlet valve actuating member, and plunger,

(l) said base plate having cutout portions, the edges of said cutoutportions lying directly below the respective inlet valve actuatingmember and outlet valve actuating member.

13. The device of claim 10 wherein means are provided to limit thetravel of the plunger to control the volume output of the pump.

References Cited UNITED STATES PATENTS 1,988,624 1/1935 Kipp 103-1482,393,838 l/1946 Tarbox 10S-148 2,412,397 12/1946 Harper 103-1482,922,379 1/1960 Schultz 103-l48 3,359,910 12/1967 Latham 103-1493,437,050 4/1969 Hrdina 103,-148

DONLEY I. STOCKING, Primary Examiner WLLBUR I. GOODLIN, AssistantExaminer U.S. Cl. X.R. 103-149

